Water cooling arrangement for dental drill



April 12, 1955 J. H. BLAIR WATER COOLING ARRANGEMENT FOR DENTAL DRILL Filed Sept. 11, 195:5

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JAMES /7. 1524/2 United States Patent WATER COOLING ARRANGEMENT FOR DENTAL DRILL James H. Blair, New York, N. Y., assignor to Chayes Dental Instrument Company, New York, N. Y.

Application September 11, 1953, Serial No. 379,712

4 Claims. (Cl. 32-28) This invention relates to a water cooling arrangement for a dental drill and more particularly a water cooled gluiilhing and drill spray for a hand piece of a dental In the past, water cooling spray attachments have been provided for dental drills, that is, they are provided as an auxiliary attachment to be clipped onto the side of the drill and provide a jet of water directed to the end of the bit where the drilling operation occurs to provide a coolingelfect on the cutting bit. In the past the dental drills have been operated at comparatively low R. P. M. speeds and at the usual R. P. M. speeds the only heat created was directly at the edge or end of the cutting bit. Due to the development of dental hand pieces that are driven at exceptionally high R. P. M. speeds (13.000 to 20,000 R. P. M.), the problem of cooling with a fluid (water) circulation has changed, not only increasing the amount of heat developed by the cutting or grinding bit, but because of the exceptionally small end of the dental hand piece, there is a tendency to develop heat between the bushing and the drive shaft or chuck at the end bearing of the hand piece.

It is an object of this invention to provide a dental hand piece with a water cooling arrangement at the end of the hand piece to prevent the hand piece from overheating.

Another object of this invention is to provide a dental hand piece with a water cooling arrangement at the end and a spray from the end of the hand piece to assist in cooling the cutting bit.

A still further object of this invention is to provide a dental hand piece with a Water cooling arrangement at the end of the hand piece and a spray from the end of the hand piece to assist in cooling the cutting bit in which the water cooling arrangement in addition increases the temperature of the water that impinges with the cutting bit and tooth.

Other objects of this invention shall be apparent by reference to the accompanying detailed description and the drawings in which:

Fig. 1 illustrates a side elevational view of an angle end for a dental hand piece,

Fig. 2 is a plan view taken on line 2-2 of Fig. 1,

Fig. 3 is a detail View taken on line 33 of Fig. 2,

Fig. 4 is an enlarged plan view of the check face of the angle and illustrated in Fig. l, and

Fig. 5 is a cross sectional view taken on line 5-5 of Fig. 4.

Referring to Figs. 1 and 2 there is illustrated the end portion of a dental hand piece. In this particular instance the end portion is an angle element 10, that is, this particular end piece retains the drilling bit at an angle to the drive shaft that descends through the hand piece to the angle element 10. The mechanical drive and construction of element is not of importance to this invention. Rather, this invention is only concerned with the water tube 11 that is aifixed to the side of the hand piece. Tube 11 at one end thereof is permanently mounted into a head piece 12. At the opposite end tube 11 is mounted in a ball type joint 14. The opposite end of the ball joint 14 is in turn connected to a tube or hose (not shown). The tube leading to the ball joint 14 is connected to a water supply (not shown). In order that the tube 11 may be retained in a tight fitting relation with angle element 10, a U clamp 15 (Figs. 2 and 3) is fitted into the angle element surrounding the tube 11.

Referring to Figs. 4 and 5 it is apparent that the head 2,705,838 Patented Apr. 12, 1955 piece 12 is brazed to the side of the angle element 10 adjacent to the bit mounting face 16 and tube 11 is shown mounted in a bore 17 of the head piece 12. The bit mounting face of angle element 10 is comprised of a threadably secured nut 21, that is, the upper portion of nut 21 is-provided with an external thread 22 that mates with and is threaded to an internal thread 23 of the angle element 10. Nut 21 is also provided with an abutting shoulder 24 which will abut against the end of wall 20 of the angle element 10. Nut 21 is also provided with a recessed portion 25. Nut 21 is also provided with a central bore 26. A stainless steel bushing 27 is mounted in bore 26. Bushing 27 is fitted into bore 26 to float or rotate freely therein. Bushing 27 is provided with an internal bore 28 through which the tool bit is in turn mounted to an internal chuck in angle element 10 (not shown). Bushing 27 is also provided with a recessed portion 29 that is in alignment with the recess of nut 21. Thus the recess 25 of nut 21 and the recess 29 of bushing 27 forms a peripheral chamber through which water is circulated to cool bushing 26. A cross bore 18 is drilled through tube 11, the head piece 12 and penetrates the wall 20 of the angle element 10 and also penetrates nut 21 passing into the recessed portion 25. This drilled bore must in turn be plugged on its outer extremity, that is, in the wall of element 12. The construction of nut 21 may be varied instead of depending upon the single bore 18 penetrating to the recessed portion 25, nut 21 may be provided with a peripheral groove 30 which connects recess 25 with the outer periphery of the threaded portion 22 as illustrated in Fig. 5. With this construction, nut 21 may be removed and reinserted and the peripheral groove 30 may be easily aligned with bore 18. Thus it is apparent with the construction illustrated in Fig. 5 that water entering through tube 11 will pass through bore 18 into the fluid chamber surrounding bushing 27 thus providing a water cooled jacket for bushing 27. In addition to the water cooled jacket, one or more bores 31 may be drilled into outer face 32 of the element but in each instance the bore 31 will be drilled on a particular angle and will be drilled to enter into the water chamber formed by recesses 25 and 29. This bore 31 thus provides a fluid passage so that the water that is pumped into the fluid chamber about bushing 27, being under pressure, this water will be jetted through bore 31 and thus ejected in a fine stream on the particular angle of bore 31 and thus aimed to impinge upon the cutting edge of a bit mounted in the hand piece (not shown). It is apparent with this construction that tube 11 may be connected to an ordinary water supply where there is suflicient pressure or tube 11 may be connected to an auxiliary pump (not shown) and the pump in turn connected in turn to a fluid supply (not shown). In either case, the water supplied may be too cool for spraying directly to the cutting bit and at the same time impinging upon the tooth of a patient. But in the embodiment illustrated, although the water may be cool or cold when supplied through tube 11, by the time it has circulated in the fluid chamber surrounding the bushing 27, it will be considerably Warrned because of the heat developed by the high R. P. M. drive through bushing 27. Thus the water that is sprayed to impinge upon the bit and the tooth will be of a desired temperature and cannot cause discomfort to the patient. Although there is illustrated a single bore 31 to produce a single jet stream, it is within the scope of this invention to provide a plurality of bores 31. Although tube 11 has been illustrated as mounted externally of the dental hand piece and the angle element 10, it is conceivable that tube 11 may be mounted internally to accomplish the same result. Although bushing 27 has been illustrated with a floating or loose fit in this embodiment of the invention, it is likewise within the concept of this invention to provide a tight fitting bushing and still obtain the same general effect as described in this embodiment.

Various changes may be made regarding the size of the water cooling cavity or the general location of the water cooling cavity and various changes may be made to the size of jet bore, its shape or its manner of varying the jet spray without departing from the spirit of this invention and this invention shall be limited only by the appended claims.

What is claimed is:

1. The combination with the hand piece of a dental drill, a removable tool bearing end and bushing, said bearing end and bushing provided with a water jacket surrounding the central circular periphery of the bushing, a water tube atfixed to the exterior of the dental hand piece, said water tube connected to said water jacket to carry water to be circulated through said water jacket.

2. The combination with the hand piece of a dental drill, a removable tool bearing end and bushing, said bearing end and bushing provided with a water jacket surrounding the central circular periphery of the bushing, said end piece provided with a jet aperture that extends into said water jacket, a water tube affixed to the exterior of the dental hand piece, said water tube connected to said Water jacket to carry Water to be circulated through said water jacket and be expelled through said jet aperture.

3. In a device according to claim 2 in which there are a tlllurality of jet apertures that extend into said water jac et.

4. The combination withl'the hand piece of a dental drill, a removable tool bearing end and bushing, said bearing end and bushing provided with a water jacket surrounding the central circular periphery of the bushing, said tool bearing end provided with a jet aperture that is connected to said water jacket, a water tube passing through the dental hand piece, said water tube connected to said water jacket to carry water to be circulated through said water jacket and be expelled through said jet aperture.

References Cited in the file of this patent UNITED STATES PATENTS 2,442,033 Brantly et al. May 25, 1948 

